The board has 4 installed, a black set on one side whick looks bigger, and a white set on the other whick look smaller. The extra set looks like it is the same size as the white ones on the board. Is there a purpose?

Not familiar with current hype product but its probably the newer idea/version of the old State board which was asymetric, meaning the toe side edge has more fin in order to help edge better on that edge

Im guessing you got the Hyperlite Forefront, and Jason is correct in that the larger fins go on the toe-side edge so help facilitate eaiser toe-side learning, much like the hyperlite State. they come with extra white fins with the idea that once you have gotten comfortable with your toe-side techniques, etc. then you go ahead on pop the smaller fins on so you have the same size fins on both edges. but its obviously up to you how you set your fins up. try them both out and see what you like best. hope this helps.